I agree with your opinion about a young age should be stopped from gambling, but the problem is they can easily access every website with internet connection which available everywhere. They can access gambling website in the cafe or the malls.
I think the governments which are prohibit gambling in their country as trying hard to block every gambling site so people especially young age cannot access that site but you know, the internet connection is not hard to find in today. Perhaps, it is our jobs to take care of the young age around us or even our kids to stay away from gambling. I am sure if we can explain to them about how dangerous gambling games for their life, they will understand and they will obey us.
Besides that, we need to make a friendly approaching to young age, so they know that playing gambling is not good in their ages and even it will risk their life too in the future. And soon, after the young age realizes the risk of gambling game, they will become aware that they don't have to use gambling as one way to having fun and there is any other activity that they can use in their free time.
This is only more the reason for more regulations to attempt to stop this sort of behavior, and I think the companies that are attempting to skirt these rules should be held liable for the problems that they're going to cause down the line because they won't ensure that their site (to the best of their knowledge) isn't being used by those under 18. Companies know exactly what they're doing and they're reaping the rewards of letting underage people gamble, though they should soon face the legal consequences.
I think the government can stop them by creating a regulation to control the site even if the site is not hosted in their country and they can make cooperation with the other country to control the gambling spreading.
But it's difficult to know their site is not being used by younger age because the government and the gambling websites don't know who the person that is playing gambling on their site is. They will feel difficult if the gambler using VPN to hide their IP from tracking.
And in the crypto gambling, it's very difficult to know who owns the wallet for the gambling transaction even the gambling website is already told to the government about their wallet for the transaction.
Perhaps, we need to gather and talk about the real solution, but the most important is by watching the young ages to not making illegal things that can make their lives in the dangerous.